Library card catalogs offer an easy way to search for and locate books throughout a library system. Each card provides specific information on the author, title, subject and location of the book in the facility and at satellite branches.


The author's name is typically found at the top of every card catalog entry. If there is no specific author, the name of a company or organization that produced the title is listed.


The title is the second entry on each card. It appears first when the card is part of an index of titles.


Card catalogs arranged by author or title will have a section at the bottom of each card for three to five subjects. Card catalogs arranged by subject will have the main subject of the book listed at the top of the card.


Catalog cards all contain an ISBN (International Standard Book Number). The ISBN allows for further indexing of all titles that the library owns, making it easier for employees and visitors to locate a specific book.

Dewey Decimal Classification

The Dewey Decimal Classification helps each library arrange books by specific categories. A card catalog will usually list the DDC number on the top left corner of the card.